Dispensing nozzle structure for photographic processing apparatus



3,142,242 FOR PHOTOGRAPHIC RAT July 28, 1964 H. E. ERIKSON DISPENSINGNOZZLE STRUCTURE PROCESSING APPA US 2 Sheets-Sheet 1 Filed Dec. 14, 1961INVENTOR. 24mm 6. MW MMWL ATTORN EYS July 28, 1964 H. E. ERIKSON3,142,242 DISPENSING NOZZLE STRUCTURE FOR PHOTOGRAPHIC Filed Dec. 14,1961 PROCESSING APPARATUS 2 Sheets-Sheet 2 (D N O N f: I; i m L co cuINVENTQR. M5, M

AT TOR'NEYS United States Patent 3 142 242 DESPENSENG N FER PHGTO-GRAPHEC G AEPPARATUS Herman Erilrson, Winchester, Mass, assignor to Thisinvention relates to photographic processing apparatus and particularlyto apparatus for processing a photographic image-recording sheet bydistributing a rocessing fluid in a thin layer in contact with saidsheet and another sheet superposed therewith.

A number of different forms of devices have been proposed forsuperposing a pair of photographic sheets and distributing a processingfluid in a layer between the sheets. Such devices generally include apair of juxtaposed pressure-applying members between which the sheetsare advanced into superposition and means for supplying the processingfluid to a space between the sheets for spreading in a layertherebetween during movement of the sheets in superposition relative toand between the pressure-applying members. Devices of this type areparticularly designed to produce a photographic transfer print directlyfrom an exposed image-recording sheet material, by processes of the typedisclosed in Us. Patents Nos. 2,543,181, issued February 27, 1951, and2,662,822, issued December 15, 1953, both in the name of Edwin H. Land.in these processes, termed silver halide diffusion-transfer reversalprocesses, an exposed photosensitive image-recording sheet, preferablyincluding as the photosensitive material thereof a gelatino silverhalide emulsion, is superposed with a second sheet which functions as asupport for an image-receptive layer in which a visible print of alatent image in the photosensitive material is produced. A fluidprocessing composition is distributed in a thin layer between thesuperposed sheets to form a sandwich in which the latent image in thephotosensitive material is developed and a positive transfer print isproduced in a layer (which may comprise the fluid) supported preferablyon the second sheet. The processing fluid may contain, for example, anaqueous alkaline solution of a silver halide developer such ashydroquinone, and a silver halide solvent such as sodium thiosulphate.This processing fluid, when distributed in contact with the silverhalide emulsion, causes the exposed silver halide to be reduced tosilver and forms a watersoluble complex silver salt from unreducedsilver halide of the photosensitive sheet, the complex silver salt beingdiffusible through the layer of fluid to an image-receptive layer whereit is reduced to silver to form a positive print.

in silver halide diffusion-transfer reversal processes of the typedescribed, reduction of exposed silver halide and formation anddiffusion of a soluble silver complex commences immediately as theprocessing fluid contacts the exposed silver halide emulsion and isabsorbed thereby, and proceeds at a rate dependent upon the physical andreaction characteristics of the particular ingredients of the processingfluid and emulsion. When processes in which a positive transfer image isformed on or in a layer carried by the second sheet, it is importantthat the two sheets be properly superpositioned before image formationhas advanced to any appreciable extent or impairment of the transferimage may result. Apparatus designed heretofore for performing processesof this type generally includes a pair of pressure-applying membersdefining a convergent gap through which the two sheets are moved alongconvergent paths into superposition and means for supplying theprocessing fluid to the convergent space between the sheets. Frequentlyin apparatus of this type, the fluid is allowed to contact areas of the3,142,242 Patented July 28, 1964 "ice photosensitive material at alocation spaced from the location at which these same areas of thephotosensitive material are superposed with the second sheet. This condition is permissible as long as the sheets are advanced at comparativelyrapid linear rates, e.g., several inches to several feet per second,such that the time lapse between fluid contact and superpositioning isso short that the reaction does not progress to any appreciable extent.However, conditions which may be permissible at comparatively rapidsheet advancement rates often cannot be tolerated at comparatively slowsheet advancement rates such as, for example, one or two inches perminute.

Accordingly, objects of the invention are: to provide novel and improvedphotographic apparatus for treating an exposed photosensitiveimage-recording sheet with a fluid applied to the sheet as a layersandwiched between the image-recording sheet and other sheet in such amanner as to permit advancement of the sheets at a relatively slowlinear rate; and to provide photographic procssing apparatus asdescribed for distributing a fluid processing composition as a layeroetween a photosensitive sheet and a second sheet superposed therewith,in which the processing fluid is prevented from contacting thephotosensitive sheet until the photosensitive and second sheets aresuperposed substantially in the relative positions required for properformation of a positive image by diffusion transfer reversal.

Another object of the invention is to provide photographic processingapparatus as described comprising a nozzle including a pair ofjuxtaposed thin, flexible lips adapted to extend well into a convergentspace between the superposed sheets to a position at or closely adjacentthe position at which adjacent areas of the sheets are properly locatedin superposition, for delaying contact between said fluid and thephotosensitive image-recording sheet.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

The invention accordingly comprises the apparatus possessing theconstruction, combination of elements and arrangement of parts which areexemplified in the following detailed disclosure, and the scope of theapplication of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention,reference should be had to the following detailed description taken inconnection with the accompanying drawings wherein:

FIGURE 1 is a perspective view, partially in section with parts brokenaway, illustrating photographic processing apparatus embodying theinvention;

FIG. 2 is a fragmentary, sectional View of the apparatus of FEGURE 1,the section being taken substantially midway between the sides of theapparatus; and

FIG. 3 is a view similar to FIG. 2 of another embodiment of theapparatus of the invention.

The processing apparatus of the invention is adapted for useindependently or" other apparatus for the purpose of treating exposedphotosensitive image-recording sheet materials to produce positiveprints; or it may be incorporated in the structure of a number ofdifferent types of photographic apparatus such as cameras and documentcopiers which include means for photoexposing the imagerecording sheet.The apparatus is particularly useful for processing the image-recordingsheet as the latter is being moved continuously through the apparatus ata relatively slow rate, i.e., at a rate such that prior art processingequipment of this type is unsuitable because it would permit thereactions between the photosensitive material and the processing fluidto advance to too great an extent prior to proper superpositioning ofthe sheets. The invention overcomes this problem with a constructionwhich provides for the introduction of a processing fluid into aconvergent space between the sheets while permitting the fluid tocontact the sheets substantially only in areas thereof which have been,or are very close to being properly superposed; i.e., spaced from oneanother by a distance approximately equal to the desired thickness ofthe layer of processing fluid.

Reference is now made to FIGS. 1 and 2 of the drawings in which isillustrated photographic apparatus embodying the invention and generallycomprising a pair of pressure-applying members for superposing a pair ofsheets and means for supplying and dispensing a processing fluid fordistribution between the sheets. The pressure-applying members are shownin the form of a pair of rigid, cylindrical rolls and 12, positionedadjacent one another with their axes substantially parallel so as todefine a convergent passage. The pressure-applying members, while beingillustrated as rolls, may take other forms including bars which arefixed with respect to one another and include convergent surfacesdefining a convergent passage. Rolls 10 and 12 are preferably mountedfor rotation about their axes by suitable means (not shown) and may beretained in fixed position with respect to one another so that the widthof the passage defined by the closest portions of the peripheralsurfaces of the rolls is fixed, or in an alternative form, may bemovable toward and apart from one another but with the maximumseparation being limited so that the maximum width of the passage, atany point, is fixed.

A pair of sheets, including a photosensitive imagerecording sheet 14 anda second or image-receiving sheet 16, are guided between rolls alongconvergent paths into superposition with one another within theconvergent passage defined by the rolls. The photosensitive sheet maycomprise a layer of a photosensitive material such as a gelatino silverhalide emulsion carried on a suitable thin flexible support formed ofany of the materials generally used in photography including for examplepaper, organic plastics, foils, and the like. The second sheet alsocomprises a thin flexible material of the type generally used inphotographic processes. The two sheets are guided around portions of thesurfaces of the juxtaposed rolls into the convergent gap between therolls so as to define a convergent space into which a processing fluidis introduced for spreading in a layer between the sheets duringmovement of the sheets relative to and between the pressure-applyingrolls. Movement of the sheets between the pressure-applying rolls can beeffected, either by pulling on the sheets, or by rotating the rollsthemselves.

The means for supplying and dispensing the processing fluid between thesheets comprise a nozzle 18 approximately equal in width to the width ofthe sheets between which the fluid is to be distributed. The nozzleincludes a triangular shaped, divergent passage 20, diverging from aconduit 22, located at one end of the nozzle and through which fluid isintroduced into the nozzle, to a discharge mouth 24 at the opposite endof the nozzle, the discharge mouth extending from side to side of thenozzle and being approximately equal in length to the width of the areaof the photosensitive sheet to be treated with the processing fluid.Edge sections 26 of the nozzle, located adjacent and defining oppositesides of the discharge mouth are tapered so as to permit the nozzle toextend into the convergent space between sheets 14 and 16. In the formshown, edge sections 26 are provided with concave, cylindrically curvedouter surfaces and the nozzle is positioned with the end edges of thesesections of the nozzle extending to positions closely adjacent but outof contact with the photosensitive and second sheets. The nozzle is thuspositioned so that discharge mouth 24 is located substantially as closeas possible to the narrowest portions of the gap between rolls 10 and12.

In accordance with the invention, a pair of thin flexible lips 28 areattached to opposite sides of the nozzle at the curved surfaces of edgesections 25 so as to extend beyond the end of the nozzle and dischargemouth 24, into the convergent passage between the rolls. Lips 28 arepositioned in face to face contact with the opposed surfaces of portionsof sheets 14 and 16 located within the convergent passage between therolls and cooperate with the nozzle to define a space into which theprocessing fluid is introduced and from which the processing fluid isdistributed as a layer between the superposed sheets. Lips 28 arepreferably quite thin, being on the order of the thickness of the layerof processing fluid or the thickness of one of the sheets; and materialspreferred for use as lips 28 include organic plastics which are strong,flexible, water impermeable and inert to the reagents of the processingfluid. Materials suggested for this purpose include high densitypolyethylene, polypropylene, polyvinylidene chloride and polyethyleneterephthalate resin. As an example of the thickness of the lips, thephotosensitive and second sheets each may have a thickness on the orderof three thousandths of an inch and may range from 1 to 10 thousandths,while the layer of processing fluid spread between the sheets may rangefrom 1 to 10 thousandths of an inch; and each of lips 28 may be thinnerthan either of these sheets, for example, five ten-thousandths of aninch in thickness. The thinnest possible lips are preferred for reasonsappearing hereinafter.

The processing fluid which the apparatus is designed to dispense anddistribute between the sheets is preferably quite viscous, having aviscosity at 24 centigrade in excess of 1,000 centipoises and rangingfrom 1,000 to 200,000 centipoises. The fluid is provided in a suitablecontainer (not shown) coupled with the nozzle by a conduit and ismaintained under pressure suflicient to cause the fluid to flow from thecontainer through the conduit and nozzle into the convergent spacebetween lips 28. In the operation of the device, the fluid isdistributed in a layer between the sheets at substantially the same ratethat it is fed into the convergent space between the sheets. Movement ofthe sheets past the end edges of lips 28 causes the fluid to be drawnfrom between the lips because of the viscosity of the fluid, its surfacetension and its tendency to adhere to the sheets, and to be withdrawn bythe sheets from between the edges of lips 28. In preferred operation ofthe device, fluid pressure is just suflicient to cause the fluid toreach the space between lips 28 permitting spreading of the fluid to beaccomplished by movement of the sheets, so that the quantity of fluiddistributed between the sheets, i.e., metering of the fluid, issubstantially automatic.

The purpose of the lips, as previously indicated, is to prevent thefluid from contacting the photosensitive sheet until the last possiblemoment. In other words, the fluid is prevented from contacting thephotosensitive sheets until the latter is superposed or almostsuperposed with the second sheet with a gap between the sheetsapproximately equal to the desired thickness of the layer of processingfluid, so that diffusible image-forming substances such as solublesilver complexes formed almost immediately as the fluid contacts thephotosensitive material, are provided with a properly positioned fluidconfining surface for supporting an image-receptive layer to which theimage-forming substances are transferred to produce an image. Imageformation is also dependent upon the thickness of the layer of fluiddistributed between the sheets because the fluid must be provided insuflicient quantity to effect the desired processing while diffusiontransfer and image resolution are functionally related to the layerthickness. The thickness of the layer of fluid spread between thesuperposed sheets can be determined in various ways, preferably by thespacing of the pressure-applying members at the narrowest portion of thegap between the members; and specifically, by making the minimum spacingbetween the pressure-applying members approximately equal to thecombined thickness of the sheet materials located between thepressure-applying members at the narrowest portion of the gap and thethickness of the layer of processing fluid.

The extent to which lips 20 project into the convergent gap between thepressure-applying members is dependent upon the particular manner inwhich the thickness of the layer of fluid is to be controlled. In oneembodiment, the end edges of the lips may extend between the sheets intothe gap to the narrowest portion of the gap which, in case ofcylindrical rolls, is a plane through the axes of the rolls. In thisembodiment the width of the gap would be approximately equal to thecombined thicknesses of sheets 14 and 16, lips 28 and the layer offluid. In an alternative embodiment, the end edges of the lips extend toa position short of the narrowest portion of the gap so that the lipsare not a factor in determining the spacing between the sheets withinwhich the fluid is distributed as a layer. In this latter embodiment,the gap between the end edges of the lips, i.e., the width of the mouthdefined by the lips, is preferably equal to the thickness of the layerof fluid being spread; while the distance between the end edges of thelips and the narrowest part of the gap is maintained at a minimum. It isfor these reasons that lips 28 should be as thin as possible in orderthat they may extend as far as possible into the gap while being spaceda minimum distance apart. The processing fluid within the convergentcavity defined by the lips in the end of the nozzle, due to its motionin the direction of movement of sheets, exerts outward pressure againstthe lips thereby pressing the lips against the sheets and forming a sealbetween the lips and sheets preventing leakage of the fluid and/ or inentrapment of air between the sheets. The converging cavity defined bythe lips and nozzle, in the form shown, is open at opposite ends.Nevertheless, leakage of the fluid from the open ends of the cavitypresents no problem since the openings are relatively small, the flow offluid is continuous in the direction of the movement of the sheets andthe fluid is drawn from the cavity as a layer between the sheets at thesame rate that it is fed into the cavity from the mouth of the nozzle.Oxidation of the fluid similarly presents no problem since a relativelysmall area of the fluid is in contact with the air and even this minuteamount of fluid is constantly changing. However, the apparatus shown isdesigned primarily for continuous use, that is, continuous sheetmovement and fluid feeding; and re quires modification if it is to beemployed intermittently, that is, with intermittent sheet movement. Suchmodification involves the provision of means such as end walls forclosing the ends of the convergent cavity defined by the lips. The useof a device of this type in intermittent processes not only offers theadvantages associated with continuous processing, but the additionaladvantage of limiting the areas of the sheets in contact with the fluidduring the periods when the sheets are not in motion. Thus a saving inthe sheet materials can be effected and the sheets are not given theopportunity to absorb so much of the fluid as to be weakened and subjectto tearing when drawn between the pressure-applying members.

Another embodiment of apparatus incorporating the invention is shown inFIG. 3 of the drawings. This embodiment includes a nozzle 30 having adischarge mouth 32 and differs from the aforementioned embodiment in theconstruction of the lips. In the embodiment of FIG. 3, each of the lips,designated 34, comprises a very flexible material and tapers from arelatively thick base section 36 at which it is secured to the nozzleadjacent one side of discharge mouth 32, to a thin edge section 38extending well into the convergent gap between sheets 14 and 16. Theedge sections preferably taper to a knife or feather edge and includeouter surfaces conforming to the curvature of the sheets in the regionof the convergent gap between the pressure-applying rolls. Lips 34 maybe formed, by molding processes, of rubber and rubberlike organicplastic materials, and when tapered to a feather or knife edge, mayextend almost to the narrowest portion of the gap without influencingthe thickness of the layer of fluid or the spacing between thesuperposed sheets. Since certain changes may be made in the aboveapparatus without departing from the scope of the invention hereininvolved, it is intended that all matter contained in the abovedescription or shown in the accompanying drawings shall be interpretedas illustrative and not in a limiting sense.

What is claimed is:

1. Photographic processing apparatus comprising, in combination:

means providing a passage having walls converging to a gap ofpredetermined width for guiding a pair of photographic sheets intosuperposition during movement of said sheets through said passage;

a fluid dispensing nozzle for supplying photographic processing fluid toa convergent space between portions of said sheets in the region thereofat which said sheets converge between said walls;

said nozzle including an elongated discharge mouth bounded on oppositesides by a pair of lips including at least end edge portions which arethin and flexible and are separated by a distance not exceeding thedistance between said sheets at said gap;

means for positioning said nozzle with said lips extending into saidpassage within said convergent space between said sheets and with theouter surfaces of said lips in contact with said portions of saidsheets; and

means for supplying said processing fluid to said nozzle under pressuresufficient to cause said fluid to flow between said lips through saiddischarge mouth.

2. The photographic apparatus of claim 1 wherein said lips extend intosaid passage, with their outer surfaces substantially parallel with saidwalls to a position wherein the end edges of said lips are locatedwithin said gap.

3. The photographic apparatus of claim 1 wherein said nozzle comprises arigid section having a fluid conducting passage coupled with saiddischarge mouth and terminating at a position spaced from said gap, andsaid flexible lips extend from said rigid section toward said gap andprovide said discharge mouth.

4. The photographic apparatus of claim 3 wherein said lips comprisesheets of thin, flexible, fluid-impermeable material attached to saidrigid section of said nozzle.

5. The photographic apparatus of claim 1 wherein the thicknesses of atleast said edge portions of said lips is on the order of the thicknessof said sheets.

6. The photographic apparatus of claim 1 wherein each of said walls isconvexly curved toward the other of said walls.

7. Photographic processing apparatus for treating a photosensitiveimage-recording sheet by superposing said sheet with a second sheet anddistributing a processing fluid in a layer of predetermined thicknessbetween said sheets to form a sandwich, said apparatus comprising, incombination:

means providing a passage having walls converging to a gap ofpredetermined minimum width for guiding said sheets into superpositionand distributing said processing fluid in a layer between said sheetsduring movement thereof through said passage;

a fluid dispensing nozzle for supplying said fluid to a convergent spacebetween portions of said sheets in the region thereof at which saidsheets converge between said walls;

said nozzle including a pair of juxtaposed lips disposed on oppositesides of an elongated discharge mouth and being positioned with saidlips extending into said passage to positions adjacent said walls;

at least the end edge portions of said lips being thin and flexible;

means for positioning said nozzle with said lips within said convergentspace between said sheets, with the outer surfaces of said lips inface-to-face contact with said portions of said sheets and the innersurfaces of said lips spaced from one another by a dis- 7 tance notexceeding the thickness of said layer of fluid; and

means for supplying said processing fluid to said nozzle under pressuresuflicient to cause said fluid to flow between said lips.

8. The photographic apparatus of claim 7 wherein said minimum width ofsaid passage at said gap is approxi mately equal to the combinedthicknesses of said sandwich and said end edge portions of said lips.

9. The photographic apparatus of claim 7 wherein the thickness of atleast the end edge portion of each of said lips is on the order of thethickness of said layer of fluid being distributed between said sheets.

10. The photographic apparatus of claim 7 wherein said nozzle comprisesa rigid section terminating at a position spaced from said gap and fromsaid walls, and said lips extend from said rigid section toward saidgap.

11. The photographic apparatus of claim 10 wherein the edges of saidlips extend into said gap to the narrowest portion thereof.

12. The photographic apparatus of claim 7 wherein each of said walls isconvexly curved toward the other of said walls.

13. The photographic apparatus of claim 7 wherein said minimum width ofsaid gap is approximately equal to the combined thicknesses of saidsandwich and said end edge portions of said lips are spaced from oneanother by a distance at least equal to the thickness of said layer offluid being distributed between said sheets.

14. Photographic processing apparatus for treating a photosensitiveimage-recording sheet by superposing said sheet with a second sheet anddistributing a processing fluid in a layer of predetermined thicknessbetween said sheets to form a sandwich, said apparatus comprising, incombination:

means providing a passage having opposed walls con verging to a gap ofpredetermined minimum width for guiding said sheets into superpositionand distributing said processing fluid in a layer between said sheetsduring movement thereof through said passage;

a fluid dispensing nozzle for supplying said fluid to a convergent spacebetween portions of said sheets in the region thereof at which saidsheets converge between said walls;

. said nozzle including a substantially rigid section having an openingtherethrough, and a pair of relatively flexible undersupported lipsextending from said rigid section and defining an elongated opening atthe end edges of said lips;

means for positioning said nozzle with said rigid section spaced fromsaid walls sufficiently to permit movement of said sheets between saidrigid section and said walls without contacting said rigid section, withsaid lips extending toward said gap with the outer surface of said lipsin contact with said portions of said sheets and with the inner surfaceof said lips spaced from one another by a distance not exceeding thedistance between said sheets at said gap; and

means for supplying said processing fluid to said nozzle under pressuresuflicient to cause said fluid to flow through said opening between saidlips.

15. The photographic apparatus of claim 14 in which each of said lipstapers from a maximum thickness at said rigid section to an edge portionextending into said gap, said end edge portions of said lips are locatedin juxtaposition within said gap in contact with said sheets, and saidend edge portion of each of said lips has a thickness on the order ofthe thickness of said layer of processing fluid.

16. The photographic apparatus of claim 14 in which said rigid sectionof said nozzle is tapered and extends into said passage, and said lipscomprise a pair of flexible sheets secured to opposite sides of saidtapered portion of said rigid section and extending into said passagebeyond the end of said tapered portion.

References Cited in the file of this patent UNITED STATES PATENTS2,520,641 Land Aug. 29, 1950

1. PHOTOGRAPHIC PROCESSING APPARATUS COMPRISING, IN COMBINATION: MEANSPROVIDING A PASSAGE HAVING WALLS CONVERGING TO A GAP OF PREDETERMINEDWIDTH FOR GUIDING A PAIR OF PHOTOGRAPHIC SHEETS INTO SUPERPOSITIONDURING MOVEMENT OF SAID SHEETS THROUGH SAID PASSAGE; A FLUID DISPENSINGNOZZLE FOR SUPPLYING PHOTOGRAPHIC PROCESSING FLUID TO A CONVERGENT SPACEBETWEEN PORTIONS OF SAID SHEETS IN THE REGION THEREOF AT WHICH SAIDSHEETS CONVERGE BETWEEN SAID WALLS; SAID NOZZLE INCLUDING AN ELONGATEDDISCHARGE MOUTH BOUNDED ON OPPOSITE SIDES BY A PAIR OF LIPS INCLUDING ATLEAST END EDGE PORTIONS WHICH ARE THIN AND FLEXIBLE AND ARE SEPARATED BYA DISTANCE NOT EXCEEDING THE DISTANCE BETWEEN SAID SHEETS AT SAID GAP;